Sinclair says that iOS is all about touch and earlier versions of the mobile software always made touch targets clear. Buttons, for example, looked like buttons. But in iOS 7, Apple removed all of the platform’s button borders and instead uses only text and icons to indicate button locations.

“iOS 7’s designers have abandoned bordered buttons in favor of borderless colored text,” Sinclair wrote in a post on his blog. “I think this choice is unjustifiable. It is the root cause of my deep dislike for how it feels to use iOS 7. It introduces unnecessary tension and makes everything less usable than it ought to be.”

He continued, “Color alone simply cannot be the way to identify a button. You don’t touch a color. You touch an area. To activate a button, you must touch a spot inside of its boundary. Text floating in the middle of vast whitespace doesn’t define a boundary. Only borders define boundaries.”

The developer goes on to compare iOS 7 to iOS 6 and he makes a very strong argument that Apple’s new design is a serious step backwards where logic and usability are concerned.